Insecticide and method of making same



-Patented May 16, 1944'.

Thomas 0. Allenandltobert 1.15m, Madison,

1 Wis, assignors to Wisconsin Alumni-Research Foundation, Madison, Wis., a corporation of Wisconsin No Drawing. Application October 14,1942,

Serial No. 461,996 s '7 Claims, (01. 167-24) This invention relates to an insecticide and to the method of preparing the same. It. has special instances somewhat toxic, but in no case sufiicient to meet the requirement of the standards generreference to an insecticide which, when used in liquid form for spraying, is specially toxic to houseflies.

One object is to provide an insecticide which highly toxic to insects,.especially to houseflies, and

which is more effective and .less expensive to protime than the present forms of commercial insecticides.

A further object is to utilize a plant material which is available or can readily be grown within the United States, but which in its natural state the same species.

ally recognized for cmnmercial insecticides. This wide range'of variation exists also in the seed of sumably due to such factors as age and storage of the seed and methods. of harvest, and possibly is normally either non-toxic or insufiiciently toxic forcommercial insecticide purposes.

IA further object is to convert an otherwise insufliciently toxic plant material into a highlytoxic product for use as the toxic ingredient of an insecticide for insects, particularly houseflies, and

to further enhance the lethal properties of the said material by combining it with another toxic material.

environmental conditions associated with the wide floralrange or the plant.

, The application of heat to the-ground or powdered seedincreases or renders active to a high degree the potency of the toxic ingredients irrespective of the degree of the toxicity before treatment; As a-result of heat treatment, the seed of .the various species and of various batches of the same species can be brought'up to a substantially uniform level of toxicity higher than the degree of toxicity found in any of thespecles in the normalstate.

This is extremely important from a commercial' standpoint because it enables the insecticide producers to utilize all of the available saba- This insecticide is composed of the seed of the sabadilla plant which has been greatly enhanced or increased in toxicity over the natural state of the seed, and an organic thiocyanate, particularly Lethane, a synthetic preparation known as betabutoxy-beta-primeethiocyano-diethyl eth'er.

The sabadilla -plant, and particularly the seed thereof, has toxic properties which are not in the natural state of the plant'sufflcient'ly potent to insects to make a suitable commercial insecticide,

but which are activated or rendered highly potent by the-application of heat.

The sabadilla seed of commerpe is principally derived from plants of the Schoenocaulongenus,

thirteen species have been described. Of these species, the Schoenocaulon oflicinale, (chlect. and Chain.) A. Gray. is the principal source of tribe Veratreae, family Lilliaceae, of which over l commercial sabadilla seed. Theschoenocaulon oflicinale has been collected in Mexico, Guatemala, Honduras and Venezuela, while another species Sehoenocaulo'n drum'momiz'i, A. Gray; is prevalent in the United States, and-has been found to be most satisfactory in possessing the active principle .which is toxic to insects.

While other portions of the plant, such as the spikes, have been found to be toxic to some degree, it is not sufficient to provide a commercial source, and it has been found that the seed of the plant is the principal source of active ingredients. The toxicity of the sabadilla seed in the natural state of diflerent species varies greatly, some being practically non-toxic and others being in some dilla seed," without. regard to-the natural toxic properties and without the necessity of testing or selectingtoxic species. "Furthermore, the level of toxicity to which the application of heat raises the seed provides a product which is effective .to meet and'surpass the degree of toxicity required for commercial insecticides.-

The seedfis finely powdered or ground or comminuted, and then heated sufliciently above normal temperature and for a sufficient period of I time to develop or enhance the toxic potency to itsmaximum, and then allowed to cool down to normal temperature. A temperature of about 150 C. for a period of about one hour is the most effective. Any increase inv temperature of the powdered seed in relation to time above usual or normal temperature activates or enhances the toxicity of the material, and the degree of increase or enhancement'becomes greater as thetemperatures approach about 150 C. in relation to a time periodof about one hour. On the other hand,

temperatures beyond about 150 C., even though r the time may be varied, appear to have the effect of either not appreciably increasing the toxicity or destroying it. The application of heat above normal temperature enhances the degree or level of the toxicity of the'powdered seed, and it is readily determiriable, without experiment, .what

temperatures are most effective to'produce the desiredmaximum results in any case of particular batches of seed or species of plant being treated.

The application of heat to the. po de ed S ed may be accomplished generally in two ways and with any suitable apparatus. If the material is These differences are pre-' at high pressure.

to be used as an insecticide in dry or dusting powder form, then the powder itself can be heated in a suitable chamber and allowed to cool, after which it is ready for use. 011 the other hand, if the material is to. be used as the toxic ingredient of a liquid or spray type of insecticide, the powdered seed is mixed with a solvent or vehicle such as kerosene, and the m xture heated to the desired degree and for the proper length of time. The extract thus formed is then filtered either hot or cooled. Any of the solvents, such as petroleum hydrocarbon oi the kerosene type, commonly used for commercial spray insecticides, may be used as a solvent or vehicle for the powdered sabadilla seed.

The treatment of sabadilla seed by heat develops the toxicity thereof to the extent that a toxic material is provided which, in the proportion of one-half pound of powdered seed to one gallon of solvent, forms an insecticide for housefiies which greatly exceeds the standard requirements of the National Association of Insecticide and Disinfectant Manufacturers Oiilcial Test Insecticide for a highly toxic fly spray insecticide.

In the commercial manufacture of spray insecticides, it is desirable to produce concentrated extracts which are afterwards diluted for use. "in this event, the ore-heated dry powdered seed can be added in larger quantity, say nine or ten. pounds to a gallon of solvent at normal temperature, or the unheated powder in such quantity mixed with a gallon of solvent and the mixture heated as above described. The mixture under either of these conditions can then be zssed The resulting concentrated extract is then diluted with solvent to the pro portion of one-ha1f to one pound of the original powdered seed per gallon of solvent, and this dilution is commercially effective as a. fly spray.

We have discovered that by combining Lethane (beta-butcxy-beta-prime-thiocyanodiethyl-ether) with sabadilla seed which has been treated by the application of heat, as above described, the toxicity, particularly the lethal properties, of the combination is greatly increased over that of the treated sabadilla seed or the "Lethane alone. In fact, the synergistic relationship of the sabadilla seed and "Lethane in combination raises the toxicity of the combination to a much higher level than the additive toxicity of the components. To illustrate, where an extract of one-fourth pound of treated sabadilla in one gallon of solvent gave a 21% kill of housefiies. and a 1% Lethane" solution is practically non-toxic, the combination of the materials gave 9.48% kill. Similarly, where a one-fourth pound per gallon extract gave 21% kill and a 2% Lethane" solution gave a 35% kill, the combination killed 93% of the flies tested. In. the extract, in the proportion 01' onehalf pound of powdered seed to one gallon oi solvent, as hereinbefore referred to, the addition of 1% Lethane" produced an exceptionally high killing spray.

We claim:

1. An insecticide ofspraying consistency comprising petroleum hydrocarbon oi the kerosene type and the active principle of the seed of the sabadilla plant which has been increased intoxicity to houseflies over that of the sabadilla seed in its natural state, by the application or heat and Lethane.

2. As an insecticide of spraying consistency, an extract of petroleum hydrocarbon oi the kerosene type and the active principle of the seed of the sabadilla plant, said extract having a. toxic potency to houseflies enhanced by heat over that of the natural sabadilla seed, and Lethane."

3. A spray type of insecticide toxic to flies consisting of a solvent and the active principle oi sabedilla seed which has been heated to a temperature sufficiently above normal temperature and for a sufllcient period oi time to enhence the toxicity of the natural seed, and Lethene. 1

4. An insecticide comprising an extract of sabadilla seed and solvent which has been rendered toxic to a higher level than normal toxicity by the application of heat, and Lethane.

5. The herein described method of making an insecticide which consists in comminuting the seed of the sabadilla plant, and heating the comminuted seed in a solvent at a temperature sufiiciently above normal temperature and for a sufficient period of time to increase the toxicity thereof to insects over the natural toxicity of the seed, and then adding sufficient Lethane to the solutionto further enhance the toxicity thereof.

6. The method of making an insecticide toxicthereof in a solvent at a temperature of approximately C. for a period of approximately. one hour and agitating said seed and solvent during said extraction, and adding Lethane" to said solution in suiilcient proportion to increase the toxicity thereof.

' THOMAS C; ALLEN.

ROBERT J. DICKE. 

